From patchwork Wed Jan 22 21:43:28 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Blake X-Patchwork-Id: 11346459 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 846941820 for ; Wed, 22 Jan 2020 21:44:29 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 043602465A for ; Wed, 22 Jan 2020 21:44:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="h9z6FWMa" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 043602465A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:47372 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iuNnX-00023r-Rf for patchwork-qemu-devel@patchwork.kernel.org; Wed, 22 Jan 2020 16:44:27 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:35366) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iuNms-0001XF-2O for qemu-devel@nongnu.org; Wed, 22 Jan 2020 16:43:48 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iuNmo-0000Il-Sc for qemu-devel@nongnu.org; Wed, 22 Jan 2020 16:43:44 -0500 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:23141 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iuNmo-0000I0-Gp for qemu-devel@nongnu.org; Wed, 22 Jan 2020 16:43:42 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1579729421; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=NIYENMK/IGSpmXoGf/xMHicwVYMpgkpSuCil0QvoqKc=; b=h9z6FWMa8kYhgadpMWc7eLV0F5iqgjxwVjjPtGVctWYrFMvjYyM6DjTN9rh4s+g7nYwDi4 BGu/7deTah8d734W7OwdR1bSFnN/wZVYDcB8sgYHeTDuamgle29x/I+qemQsyaCZs8yrpx jY161SxDYO/2vRmzPLg+sd0CV50VXk0= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-391-U2bULztoPqSjxIz00n-WDQ-1; Wed, 22 Jan 2020 16:43:40 -0500 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9CE5C18C8C02; Wed, 22 Jan 2020 21:43:38 +0000 (UTC) Received: from blue.redhat.com (ovpn-117-16.phx2.redhat.com [10.3.117.16]) by smtp.corp.redhat.com (Postfix) with ESMTP id D71245C1BB; Wed, 22 Jan 2020 21:43:35 +0000 (UTC) From: Eric Blake To: qemu-devel@nongnu.org Subject: [PATCH] qemu-nbd: Removed deprecated --partition option Date: Wed, 22 Jan 2020 15:43:28 -0600 Message-Id: <20200122214328.1413664-1-eblake@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-MC-Unique: U2bULztoPqSjxIz00n-WDQ-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.81 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "reviewer:Incompatible changes" , qemu-block@nongnu.org Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" The option was deprecated in 4.0.0 (commit 0ae2d546); it's now been long enough with no complaints to follow through with that process. Signed-off-by: Eric Blake --- qemu-deprecated.texi | 49 ++++++---------- qemu-nbd.c | 133 +------------------------------------------ qemu-nbd.texi | 13 ++--- 3 files changed, 24 insertions(+), 171 deletions(-) diff --git a/qemu-deprecated.texi b/qemu-deprecated.texi index 8471eef9c22d..1b4c638db8e0 100644 --- a/qemu-deprecated.texi +++ b/qemu-deprecated.texi @@ -304,37 +304,6 @@ The above, converted to the current supported format: @section Related binaries -@subsection qemu-nbd --partition (since 4.0.0) - -The ``qemu-nbd --partition $digit'' code (also spelled @option{-P}) -can only handle MBR partitions, and has never correctly handled -logical partitions beyond partition 5. If you know the offset and -length of the partition (perhaps by using @code{sfdisk} within the -guest), you can achieve the effect of exporting just that subset of -the disk by use of the @option{--image-opts} option with a raw -blockdev using the @code{offset} and @code{size} parameters layered on -top of any other existing blockdev. For example, if partition 1 is -100MiB long starting at 1MiB, the old command: - -@code{qemu-nbd -t -P 1 -f qcow2 file.qcow2} - -can be rewritten as: - -@code{qemu-nbd -t --image-opts driver=raw,offset=1M,size=100M,file.driver=qcow2,file.backing.driver=file,file.backing.filename=file.qcow2} - -Alternatively, the @code{nbdkit} project provides a more powerful -partition filter on top of its nbd plugin, which can be used to select -an arbitrary MBR or GPT partition on top of any other full-image NBD -export. Using this to rewrite the above example results in: - -@code{qemu-nbd -t -k /tmp/sock -f qcow2 file.qcow2 &} -@code{nbdkit -f --filter=partition nbd socket=/tmp/sock partition=1} - -Note that if you are exposing the export via /dev/nbd0, it is easier -to just export the entire image and then mount only /dev/nbd0p1 than -it is to reinvoke @command{qemu-nbd -c /dev/nbd0} limited to just a -subset of the image. - @subsection qemu-img convert -n -o (since 4.2.0) All options specified in @option{-o} are image creation options, so @@ -383,3 +352,21 @@ trouble after a recent upgrade. The "autoload" parameter has been ignored since 2.12.0. All bitmaps are automatically loaded from qcow2 images. + +@section Related binaries + +@subsection qemu-nbd --partition (removed in 5.0.0) + +The ``qemu-nbd --partition $digit'' code (also spelled @option{-P}) +could only handle MBR partitions, and never correctly handled logical +partitions beyond partition 5. Exporting a partition can still be +done by utilizing the @option{--image-opts} option with a raw blockdev +using the @code{offset} and @code{size} parameters layered on top of +any other existing blockdev. For example, if partition 1 is 100MiB +long starting at 1MiB, the old command: + +@code{qemu-nbd -t -P 1 -f qcow2 file.qcow2} + +can be rewritten as: + +@code{qemu-nbd -t --image-opts driver=raw,offset=1M,size=100M,file.driver=qcow2,file.backing.driver=file,file.backing.filename=file.qcow2} diff --git a/qemu-nbd.c b/qemu-nbd.c index bc125370dd36..e6f2eb76a3f2 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -100,7 +100,6 @@ static void usage(const char *name) "\n" "Exposing part of the image:\n" " -o, --offset=OFFSET offset into the image\n" -" -P, --partition=NUM only expose partition NUM\n" " -B, --bitmap=NAME expose a persistent dirty bitmap\n" "\n" "General purpose options:\n" @@ -156,96 +155,6 @@ QEMU_COPYRIGHT "\n" , name); } -struct partition_record -{ - uint8_t bootable; - uint8_t start_head; - uint32_t start_cylinder; - uint8_t start_sector; - uint8_t system; - uint8_t end_head; - uint8_t end_cylinder; - uint8_t end_sector; - uint32_t start_sector_abs; - uint32_t nb_sectors_abs; -}; - -static void read_partition(uint8_t *p, struct partition_record *r) -{ - r->bootable = p[0]; - r->start_head = p[1]; - r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300); - r->start_sector = p[2] & 0x3f; - r->system = p[4]; - r->end_head = p[5]; - r->end_cylinder = p[7] | ((p[6] << 2) & 0x300); - r->end_sector = p[6] & 0x3f; - - r->start_sector_abs = ldl_le_p(p + 8); - r->nb_sectors_abs = ldl_le_p(p + 12); -} - -static int find_partition(BlockBackend *blk, int partition, - uint64_t *offset, uint64_t *size) -{ - struct partition_record mbr[4]; - uint8_t data[MBR_SIZE]; - int i; - int ext_partnum = 4; - int ret; - - ret = blk_pread(blk, 0, data, sizeof(data)); - if (ret < 0) { - error_report("error while reading: %s", strerror(-ret)); - exit(EXIT_FAILURE); - } - - if (data[510] != 0x55 || data[511] != 0xaa) { - return -EINVAL; - } - - for (i = 0; i < 4; i++) { - read_partition(&data[446 + 16 * i], &mbr[i]); - - if (!mbr[i].system || !mbr[i].nb_sectors_abs) { - continue; - } - - if (mbr[i].system == 0xF || mbr[i].system == 0x5) { - struct partition_record ext[4]; - uint8_t data1[MBR_SIZE]; - int j; - - ret = blk_pread(blk, mbr[i].start_sector_abs * MBR_SIZE, - data1, sizeof(data1)); - if (ret < 0) { - error_report("error while reading: %s", strerror(-ret)); - exit(EXIT_FAILURE); - } - - for (j = 0; j < 4; j++) { - read_partition(&data1[446 + 16 * j], &ext[j]); - if (!ext[j].system || !ext[j].nb_sectors_abs) { - continue; - } - - if ((ext_partnum + j + 1) == partition) { - *offset = (uint64_t)ext[j].start_sector_abs << 9; - *size = (uint64_t)ext[j].nb_sectors_abs << 9; - return 0; - } - } - ext_partnum += 4; - } else if ((i + 1) == partition) { - *offset = (uint64_t)mbr[i].start_sector_abs << 9; - *size = (uint64_t)mbr[i].nb_sectors_abs << 9; - return 0; - } - } - - return -ENOENT; -} - static void termsig_handler(int signum) { atomic_cmpxchg(&state, RUNNING, TERMINATE); @@ -620,7 +529,7 @@ int main(int argc, char **argv) int64_t fd_size; QemuOpts *sn_opts = NULL; const char *sn_id_or_name = NULL; - const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:T:D:B:L"; + const char *sopt = "hVb:o:p:rsnc:dvk:e:f:tl:x:T:D:B:L"; struct option lopt[] = { { "help", no_argument, NULL, 'h' }, { "version", no_argument, NULL, 'V' }, @@ -629,7 +538,6 @@ int main(int argc, char **argv) { "socket", required_argument, NULL, 'k' }, { "offset", required_argument, NULL, 'o' }, { "read-only", no_argument, NULL, 'r' }, - { "partition", required_argument, NULL, 'P' }, { "bitmap", required_argument, NULL, 'B' }, { "connect", required_argument, NULL, 'c' }, { "disconnect", no_argument, NULL, 'd' }, @@ -660,7 +568,6 @@ int main(int argc, char **argv) int ch; int opt_ind = 0; int flags = BDRV_O_RDWR; - int partition = 0; int ret = 0; bool seen_cache = false; bool seen_discard = false; @@ -796,15 +703,6 @@ int main(int argc, char **argv) readonly = true; flags &= ~BDRV_O_RDWR; break; - case 'P': - warn_report("The '-P' option is deprecated; use --image-opts with " - "a raw device wrapper for subset exports instead"); - if (qemu_strtoi(optarg, NULL, 0, &partition) < 0 || - partition < 1 || partition > 8) { - error_report("Invalid partition '%s'", optarg); - exit(EXIT_FAILURE); - } - break; case 'B': bitmap = optarg; break; @@ -901,7 +799,7 @@ int main(int argc, char **argv) error_report("List mode is incompatible with a file name"); exit(EXIT_FAILURE); } - if (export_name || export_description || dev_offset || partition || + if (export_name || export_description || dev_offset || device || disconnect || fmt || sn_id_or_name || bitmap || seen_aio || seen_discard || seen_cache) { error_report("List mode is incompatible with per-device settings"); @@ -1165,33 +1063,6 @@ int main(int argc, char **argv) } fd_size -= dev_offset; - if (partition) { - uint64_t limit; - - if (dev_offset) { - error_report("Cannot request partition and offset together"); - exit(EXIT_FAILURE); - } - ret = find_partition(blk, partition, &dev_offset, &limit); - if (ret < 0) { - error_report("Could not find partition %d: %s", partition, - strerror(-ret)); - exit(EXIT_FAILURE); - } - /* - * MBR partition limits are (32-bit << 9); this assert lets - * the compiler know that we can't overflow 64 bits. - */ - assert(dev_offset + limit >= dev_offset); - if (dev_offset + limit > fd_size) { - error_report("Discovered partition %d at offset %" PRIu64 - " size %" PRIu64 ", but size exceeds file length %" - PRId64, partition, dev_offset, limit, fd_size); - exit(EXIT_FAILURE); - } - fd_size = limit; - } - export = nbd_export_new(bs, dev_offset, fd_size, export_name, export_description, bitmap, readonly, shared > 1, nbd_export_closed, writethrough, NULL, diff --git a/qemu-nbd.texi b/qemu-nbd.texi index 7f55657722bd..36f4188a3f27 100644 --- a/qemu-nbd.texi +++ b/qemu-nbd.texi @@ -55,11 +55,6 @@ Force the use of the block driver for format @var{fmt} instead of auto-detecting. @item -r, --read-only Export the disk as read-only. -@item -P, --partition=@var{num} -Deprecated: Only expose MBR partition @var{num}. Understands physical -partitions 1-4 and logical partition 5. New code should instead use -@option{--image-opts} with the raw driver wrapping a subset of the -original image. @item -B, --bitmap=@var{name} If @var{filename} has a qcow2 persistent bitmap @var{name}, expose that bitmap via the ``qemu:dirty-bitmap:@var{name}'' context @@ -161,13 +156,13 @@ qemu-nbd \ --image-opts driver=raw,offset=1M,size=1M,file.driver=file,file.filename=file.raw @end example -Serve a read-only copy of just the first MBR partition of a guest -image over a Unix socket with as many as 5 simultaneous readers, with -a persistent process forked as a daemon: +Serve a read-only copy of a guest image over a Unix socket with as +many as 5 simultaneous readers, with a persistent process forked as a +daemon: @example qemu-nbd --fork --persistent --shared=5 --socket=/path/to/sock \ - --partition=1 --read-only --format=qcow2 file.qcow2 + --read-only --format=qcow2 file.qcow2 @end example Expose the guest-visible contents of a qcow2 file via a block device